Abstarct: Simultaneously with the global application of BIM (Building Information Modeling) technology in the construction industry, the application of this new method in many countries, including Iran, faces many obstacles. In order to expand the use of BIM in these areas, it is necessary to identify its obstacles and challenges. A sustainable project is the planning, monitoring and control of project delivery and support processes, taking into account the environmental, economic and social aspects of the project life cycle, processes, results and impacts, with the aim of understanding the interests of stakeholders and is carried out in a transparent, fair and ethical manner that It includes active stakeholder participation. In this thesis, first, by using the fuzzy Delphi method from the panel of experts, as well as reviewing the research background, the initial list of obstacles and challenges has been identified, confirmed, and criteria screened. As a result, out of 31 obstacles identified, 10 obstacles were recognized as the most important criteria. In the next step, by using the best-worst (BWM) method, the best and worst indicators are determined by the decision maker and a pairwise comparison is made between each of these two indicators (best and worst) and other indicators and to solve This model uses Lingo 18 software. Finally, they are ranked baxsed on the weight of the criteria. The results of the analyzes show that the most important obstacles and challenges in the application of building information modeling in sustainable projects in Iran are, respectively: the lack of precise application processes for BIM technology in first-rate sustainable buildings, The criterion of lack of clear BIM application standards in sustainable buildings has been ranked second and the criterion of lack of legal frxamework for BIM application has been ranked third.